1. Field of the Invention
The present invention relates to a method and an apparatus for controlling a traffic transfer rate based on cell capacity in a mobile communication system. More particularly, the present invention relates to a method and an apparatus for determining capacity of each cell of a base station using per cell load and for adaptively controlling a traffic transfer rate depending on a determined capacity of each cell in a mobile communication system.
2. Description of the Related Art
Due to the increasing use of smart devices, such as smart phones and tablet Personal Computers (PCs), the use of Internet content, such as web page access and video streaming, has increased exponentially in mobile communication networks. In order to efficiently handle the surging data traffic and to improve Quality of Service (QoS) and Quality of Experience (QoE), mobile operators, telecom equipment vendors and service solution vendors of the related art have incorporated functionalities of content caching and web and video traffic optimization in already deployed network equipment or installed network equipment that can provide those functionalities in the wireless networks, reducing delay and bandwidth consumption for content delivery.
The network equipment, solutions and systems aimed at providing the service enhancements in the mobile networks are collectively referred to as a service acceleration system. Commonly, the service acceleration system is placed between a core network of the wireless network and the external Internet to perform web content compression and/or bandwidth shaping or rate shaping for smooth or in-time video data transmission. The rate shaping in the service acceleration system provides the improved QoE to users and increases the operating efficiency of the operator networks.
The rate control or rate shaping of the related art is performed based on the network status estimation, which is similar to the method used for rate adjustment in wired networks. The network status estimation is performed in a way of estimating the available bandwidth and the network congestion based on the Round-Trip Time (RTT) of application packets, the spacing between TCP (Transmission Control Protocol) ACK (Acknowledgement) packets, and the receiver buffer level of user devices.
However, in the wireless link, for example, in the link between a User Equipment (UE) and a base station, the rate may often significantly vary between its minimum and maximum values depending on the channel status, such as user mobility, signal strength, interference between wireless signals, and the like. The number of active users that are connected to a base station may also be dynamically changed due to their mobility characteristics. Therefore, when used in the wireless network, the rate control or shaping mechanisms of the related art may cause various problems because it is hard to timely and accurately reflect the status of the wireless network.
The RTT of application packets, the spacing between ACK packets, or the receiver buffer level, which are used for the network status estimation of the related art, may not indicate the direct status of the wireless network, but may correspond to the indirect phenomenon which occurs some time after the network status was actually changed. Therefore, with the network status estimation of the related art, it is difficult to quickly and accurately detect the wireless network status depending on the mobility of users, the utilization of physical wireless resources, the signal interference, and the change in the number of active users. In addition, the rate control based on the inaccurate network status estimation may cause continuous over-provisioning and under-provisioning in rate and bandwidth control, thereby degrading the network operating efficiency.
Therefore, there exists a need for a method and an apparatus for controlling a traffic transfer rate based on the cell capacity in a mobile communication system.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.